This invention relates to organic nitrate esters and more particularly to aromatic nitrate esters which are useful as explosives.
The availability of high-melting nitrate esters is very limited. Pentaerythritol tetranitrate (PETN) is the highest melting of commonly available nitrate esters, but its melting point (140.degree. C.) precludes its use at temperatures in the vicinity of 150.degree. C. and above [missile systems often require explosives that can withstand short-term (30 minutes) exposure to temperatures in the vicinity of 150.degree. C. and above due to aerodynamic heating]. A higher melting (mp 158.degree.-160.degree. C.) nitrate ester, 2,4,6-trinitro-1,3,5-tris(2-hydroxyethylnitramino)benzenetrinitrate, has been reported but its availability is limited by procedures that provide low to moderate yields (approximately 50%). Thus, it would be advantageous to have available a method that provides high yields of high-melting nitrate esters to allow a wide range of melting points and sensitivities as well as short-term stability at 150.degree. C.
U.S. Pat. No. 5,081,255, titled, "High melting Aromatic Nitrate Esters," which issued Jan. 14, 1992 to Michael E. Sitzmann discloses 2,4,6-trinitro-1-(2-hydroxyethylamino)-3-(2-hydroxyethylnitramino)benzened initrate; 2,2',4,4'6,6'-hexanitro-3-(2-hydroxyethylnitramino)stilbenenitrate; 1,3,5-tris(hydroxyethyl-aminonitrate)-2,4,6-trinitrobenzene; 2,5-bis[3-(hydroxyethylaminonitrate)-2,4,6-trinitrophenyl]-1,3,4-oxadiazol e; and 2,5-bis[3-hydroxyethylaminonitrate)-5-(hydroxyethylnitraminonitrate)-2,4,6 -trinitrophenyl]-1,3,4-oxadiazole which are energetic explosive compounds having suitably high melting or decomposition points. Nevertheless, it would be desirable to provide explosives which are even more resistant to high temperatures.